Neutradol! Worked wonders on our carpets when we moved into our house and the previous owners had had a badly behaved dog. Other option is to hire a rug doctor (most of the supermarkets have them you can hire) and use that to clean the smelly bit.
Thanks every one ❤️
You can try sprinkling baking soda over area and leaving overnight then hoovering following day. Buy some pet odour neutralisers and spray those on the area. Mix hydrogen peroxide with water and spray on the area (test in a hidden area first though in case it bleaches your carpet colour), or can try mixing some essential oils with water and spraying on the area